Combination safety needle assembly and medical apparatus

ABSTRACT

A method and apparatus are provided for using a medical device ( 10 ) comprised of a medical apparatus ( 20 ) and a needle assembly ( 30 ). The needle assembly includes a needle ( 70 ) having a sharpened tip. Preferably, the medical apparatus ( 20 ) is a standard apparatus, such as a syringe or phlebotomy device. The medical apparatus ( 20 ) includes a connector ( 24 ), such as a Luer connector. The needle assembly ( 30 ) is configured so that it can be attached to the medical apparatus ( 20 ) and the sharpened tip of the needle ( 70 ) is automatically shielded after use to prevent inadvertent contact with the contaminated needle.

This application claims the benefit of Provisional application Ser. No.60/168,146 filed Nov. 29, 1999.

FIELD OF THE INVENTION

The present invention relates to needle bearing medical devices. Morespecifically, the invention relates to such devices having a retractableneedle feature for rendering the device non-reusable and safelydisposable.

BACKGROUND OF THE INVENTION

Various types of medical devices employ a needle for piercing the skinof a patient for diagnostic or therapeutic purposes. One such device isa hypodermic syringe. Handling of such needle-bearing medical devicesafter the needle is withdrawn from the patient can result intransmission of various pathogens, most notably human immune virus(HIV), to uninfected medical personnel, due to an inadvertent needlestick. Accordingly, it is desirable to provide a device for injectingmedication or withdrawing fluid, wherein the contaminated needle isenclosed after use.

DESCRIPTION OF THE DRAWINGS

All of the objects of the present invention are more fully set forthhereinafter with reference to the accompanying drawings, wherein:

FIG. 1 is a top sectional view of a combination safety needle assemblyand syringe embodying aspects of the present invention;

FIG. 2 is a side sectional view of the combined safety needle assemblyand syringe illustrated in FIG. 1;

FIG. 3 is a side sectional view of the combined safety needle assemblyand syringe illustrated in FIG. 1, shown at the end of an injectionstroke;

FIG. 4 is a side sectional view of the combined safety needle assemblyand syringe illustrated in FIG. 1, shown just prior to retraction;

FIG. 5 is a top sectional view of the combined safety needle assemblyand syringe illustrated in FIG. 1 shown after retraction; and

FIG. 6 is an exploded perspective view of the combination safety needleassembly and syringe illustrated in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings in general and to FIG. 1 specifically, acombination medical device 20 and safety needle assembly 30 isdesignated generally 10. The needle assembly 30 is connectable with themedical device 20, and includes a needle 70 having a sharpened tip.After use, the needle 70 is automatically shielded to preventinadvertent contact with the contaminated needle.

Preferably, the needle assembly 30 is configured to cooperate with avariety of standard medical devices, such as a hypodermic syringe. Inthis way, medical devices that are currently widely available can beused with a needle assembly that automatically shields the needle afteruse.

Accordingly, the needle assembly and needle assembly may be sterilizedand sealed together in a single sterile package to be assembled by amedical professional prior to use. However, preferably, the needleassembly is sterilized and sealed in a sterile package separate from theneedle assembly. The needle assembly can then be used with a separatelypackaged sterile medical device of the user's choosing.

In the drawings and the following description needle assembly 30 isillustrated and described in connection with a hypodermic syringe 20,which is the preferred combination. The syringe 20 includes a generallycylindrical housing or barrel 22 having a hollow interior forming afluid chamber. The forward end of the barrel forms an end wall and hasan opening through which medicine can flow. A connector 24, in the formof a Luer fitting, is formed on the forward end of the barrel 22. Apiston 28 forms a fluid tight seal with the interior of the barrel 22. Aplunger 27 connected to the piston 28 is operable to reciprocallydisplace the piston within the barrel 22 to draw fluid into the barrelor expel fluid from the barrel.

The needle assembly 30 includes a generally cylindrical housing 40. Asdiscussed further below, the housing 40 operates as a shield to enclosethe needle after use to prevent inadvertent contact with thecontaminated needle.

The rearward end of the housing is generally open forming a socket forreceiving the syringe 20. The forward end of the housing 40 forms areduced diameter tip 42 having an opening through which the needle 70extends. Finger tabs 45 are formed at the rearward end of the housing40. The finger tabs provide a surface for the medical professional toengage during injection of fluid from or aspiration of fluid into thesyringe 20.

The needle assembly 30 further comprises an adapter 50 for attaching theneedle assembly 30 to the syringe 20. The adapter 50 comprises agenerally cylindrical body 52 having a connector 54 extending from therearward end of the body. In the present instance, the connector 54 is athreaded stem that cooperates with the Luer fitting 24 of the syringe20. However, a variety of different connectors can be used. In addition,it may be desirable to include a lock, such as a Luer lock, forsubstantially permanently connecting the needle assembly 30 to thesyringe 20.

The needle 70 is fixedly attached to the adapter 50, preferably by anadhesive. A spring 75 is disposed between the housing 40 and the adapter50, biasing the adapter 50 and the attached needle 70 rearwardly. Aneedle retainer 60 releasably retains the needle 70 against the bias ofthe spring 75.

The needle retainer is disposed within the adapter 50. The needleretainer comprises a generally cylindrical hub 61 and a pair of radiallydeformable arms 62 extending radially outwardly from the hub. A detent63 is formed on the end of each arm 62. The detents 63 engage sockets 44formed in the forward end of the housing 40.

A circumferential flange 68 is formed on the exterior of the needleretainer hub 61 and engages an annular recess 55 in the adapter 50. Thecooperation of the flange 68 and the recess 55 impedes rearward movementof the adapter 50 relative to the needle retainer 60. In this way, theneedle retainer 60 retains the adapter 50 and the attached needle 70against the rearward bias of the spring 75.

The adapter 50 is cooperable with the needle retainer 60 to effectuateretraction. Specifically, upon forward displacement of the adapter 50,the forward end of the adapter engages the needle retainer arms 62,thereby displacing the arms radially inwardly until the detents 63 aredisplaced out of registration with the sockets 44 in the housing 40. Thespring 75 then propels the needle 70, needle retainer 60, adapter 50 andthe syringe 20 rearwardly.

The spring 75 is a compression spring preferably made from stainlesssteel or other metal. The spring is sized to fit over the needle andwithin the arms of the needle retainer. In addition, the spring hasadequate free length and spring force to ensure that the needle fullyretracts into the housing 40 of the needle assembly 30.

The needle assembly 30 preferably also includes a locking mechanism forpreventing continued rearward displacement of the needle 70 afterretraction and for preventing re-extension of the needle afterretraction. Specifically, a pair of radially deformable locking arms 64extend from the hub 61 of the needle retainer 60. A locking tab 65projects radially outwardly from the forward end of each locking arm 64.The locking tabs 65 engage a pair of guide slots 43 formed in theinterior surface of the needle assembly housing 40. A pair of lockoutsockets 47 are formed in the housing 40 adjacent the rearward end of theguide slots 43. When the needle 70 and attached components are retractedrearwardly, the locking tabs 65 engage the lockout sockets 47 to lockthe needle and attached components against further axial displacementrearwardly or forwardly.

The locking arms 64 extend generally axially from the hub 61 and aredisposed radially inwardly from the body 52 of the adapter 50. In thisway, when the adapter body 52 is displaced forwardly into contact withthe needle retainer arms 62, the adapter body 52 does not engage thelocking arms 64.

In the present instance, the needle assembly 30 further comprises arigid conduit 69 that extends between the adapter 50 and the housing 40,projecting forwardly through the tip 42 of the housing. The conduit 69provides an alignment path for attaching the needle 70 to the adapter 50after assembly of the remaining components of the needle assembly 30.

Configured in this way, the device 10 operates as follows. The syringe20 is inserted into the rearward opened end of the needle assembly 30until the Luer fitting 24 of the syringe engages the connector 54. Theconnector 54 is then threaded into the Luer fitting 24 to attach theneedle assembly 30 to the syringe 20. The medical professional may thenaspirate fluid into the syringe 20 by displacing the plunger 27rearwardly within the barrel 22. Alternatively, the syringe 20 may bepre-filled with a measured dose of medicine. The fluid is expelled fromthe syringe 20 by displacing the plunger 27 forwardly.

At the end of the injection stroke, the piston 28 abuts the forward endof the interior of the barrel 22, as shown in FIG. 3. Continued forwarddisplacement of the plunger displaces the adapter 50 forwardly, suchthat the adapter engages the needle retainer arms 62, displacing thearms radially inwardly until the detents 63 are displaced out ofregistration with the sockets 44 in the housing, as shown in FIG. 4.This releases the needle for retraction by the spring after the medicalprofessional releases the plunger. The needle 70, adapter 50, needleretainer 60 and syringe 20 are then displaced rearwardly under thebiasing force of the spring until the sharpened tip of the needle isenclosed within the housing 40, thereby shielding the contaminatedneedle against inadvertent contact, as shown in FIG. 5. Afterretraction, the lockout tabs 65 deform radially outwardly to engage thelockout sockets 47 in the housing to lock the needle against furtherretraction or inadvertent re-extension.

In the foregoing description, the needle 70 is described as beingretracted into the housing 40. However, the motion can also be viewed asthe housing 40 extending over the needle 70. Accordingly, thedescription uses the term retraction to describe relative motion betweenthe needle 70 and another element, namely the housing 40, that causesthe sharpened tip of the needle to be enclosed to prevent inadvertentneedle sticks.

The terms and expressions which have been employed are used as terms ofdescription and not of limitation. There is no intention in the use ofsuch terms and expressions of excluding any equivalents of the featuresshown and described or portions thereof. It is recognized, however, thatvarious modifications are possible within the scope and spirit of theinvention.

For instance, the needle assembly has been described in connection witha standard hypodermic syringe that can be used to draw a dose ofmedicine and inject the medicine into a patient. However, the needleassembly can also be used in connection with a number of other medicaldevices. One such example is a phlebotomy device used for collectingblood samples. Another example is a pre-filled device, such as a syringethat is pre-filled with a measured does of medicine. Accordingly, theneedle assembly can be used in connection with a variety of medicaldevices.

In addition, as described above in connection with the preferredembodiment, the needle and needle assembly are substantially permanentlyattached to the syringe. However, it may be desirable to provide areleasable connection between the medical device and the needleassembly. In this way, after use the shielded needle assembly can besafely removed and disposed of, and the medical device can be reusedwith a new uncontaminated needle assembly or the medical device can beused in a separate procedure. For instance, if the medical device isused to collect a fluid specimen, the needle assembly may be removed andthen the medical device can be used to dispense the collected fluid intoa device that analyzes the collected fluid.

1. A medical device, comprising: a syringe, comprising: a barrel; aplunger slidably displaceable within the barrel; a needle assembly,comprising: a housing adapted to receive the syringe; a needle operablebetween an extended position in which the needle projects forwardly fromthe housing and a retracted position in which the sharpened tip of theneedle is enclosed within the housing; a biasing element biasing theneedle toward the retracted position; a needle retainer releasablyretaining the needle in the extended position against the bias of thebiasing element; a hub that is axially displaceable relative to theneedle retainer to effectuate retraction of the needle; wherein uponforward displacement of the syringe relative to the needle retainer, theneedle is released for retraction so that the biasing element retractsthe needle into the housing.
 2. The medical device of claim 1 whereinthe biasing element displaces the syringe rearwardly upon actuation ofretraction of the needle.
 3. The medical device of claim 1 comprising aconnector for connecting the syringe to the needle assembly.
 4. Themedical device of claim 1 wherein the needle retainer comprises aradially deformable arm engaging the housing, wherein the hub displacesthe arm radially inwardly to effectuate retraction of the needle.
 5. Asafety medical device, comprising: a medical apparatus comprising: ahousing; and a first connector attached to the housing; a shieldedneedle assembly, comprising: a needle having a sharpened tip; a shieldsurrounding at least a portion of the housing, operable between aretracted position in which the sharpened tip of the needle projectsforwardly from the shield and an extended position in which thesharpened tip of the needle is enclosed within the shield; a secondconnector cooperable with the first connector to attach the needle tothe housing; a biasing element biasing the shield forwardly relative tothe housing toward the extended position; a retainer releasablyretaining the shield in the retracted position against the bias of thebiasing element; and means for releasing the shield from the retainer inresponse to advancing the housing forwardly relative to the shield,wherein upon releasing the shield, the biasing element displaces theshield into the extended position.
 6. The safety medical device of claim5, wherein the needle is fixedly attached to the second connector. 7.The safety medical device of claim 5 comprising an actuator connectedwith the second connector, and configured to engage the needle retainerupon axial advancement of the housing relative to the shield.
 8. Thesafety medical device of claim 5, wherein the retainer comprises aradially deformable arm.
 9. The safety medical device of claim 8comprising an actuator connected with the second connector, andconfigured to radially deform the retainer arm upon axial advancement ofthe housing relative to the shield.
 10. The safety medical device ofclaim 5 wherein the medical apparatus comprises a plunger slidablewithin the housing, and the housing comprises a forward end wall suchthat advancing the plunger forwardly displaces the plunger intoengagement with the end wall, and continued advancement of the plungerdisplaces the housing forwardly relative to the shield to release theshield from the retainer.
 11. The safety medical device of claim 5,comprising a lock for automatically substantially permanently lockingthe shield after the shield is displaced into the extended position toprevent displacement of the shield relative to the needle after theshield is extended.
 12. The safety medical device of claim 11 whereinthe lock comprises a radially deformable locking arm and the shieldcomprises a recess that cooperates with the locking arm.
 13. The safetymedical device of claim 5 wherein the shield comprises a pair of flangesprojecting radially outwardly and configured to provide a surface for auser to engage during use of the device.
 14. The safety medical deviceof claim 5 wherein the second connector is cooperable with the firstconnector to substantially permanently attach the needle to the housing.15. A method for assembling and using a safety medical device,comprising the steps of: providing a sterile needle assembly, comprisinga needle having a sharpened tip, a shield and a hub having a firstconnector; providing a sterile medical apparatus, comprising a housingand a second connector; sealing the sterile needle assembly and thesterile medical apparatus within one or more containers to preventcontamination of the needle assembly and medical apparatus from becomingcontaminated; removing the needle assembly and medical apparatus fromthe one or more containers; connecting the first connector to the secondconnector to attach the needle assembly to the medical apparatus;performing a medical procedure with the combined medical apparatus andneedle assembly; retaining the shield against advancing over thesharpened tip of the needle during the step of performing a medicalprocedure; automatically releasing the shield and displacing the shieldto enclose the sharpened tip of the needle in response to axialdisplacement of the hub relative to the shield.
 16. A method forassembling and using a safety medical device, comprising the steps of:providing a sterile needle assembly, comprising a needle having asharpened tip, a shield and a hub having a first connector; providing asterile medical apparatus, comprising a barrel for receiving medicine, aplunger slidable within the barrel, and a second connector; sealing thesterile needle assembly and the sterile medical apparatus within one ormore containers to prevent the needle assembly and medical apparatusfrom becoming contaminated; removing the needle assembly and medicalapparatus from the one or more containers; connecting the firstconnector to the second connector to attach the needle assembly to themedical apparatus; injecting medicine from the barrel and through theattached needle assembly by displacing the plunger forwardly within thebarrel; retaining the shield against advancing over the sharpened tip ofthe needle during the step of injecting medicine; axially displacing thehub relative to the shield to automatically releasing the shield anddisplacing the shield to enclose the sharpened tip of the needle inresponse to axial displacement of the plunger.
 17. The method of claim16, wherein the first connector and second connector are cooperatingLuer connectors.
 18. The method of claim 16 wherein the needle assemblycomprises a biasing element, and the step of automatically releasing theshield and displacing the shield comprises automatically advancing theshield with the spring after the shield is released.
 19. The method ofclaim 16 comprising the step of automatically locking the shield toprevent axial displacement of the shield relative to the needle afterthe shield encloses the sharpened tip of the needle.